Comparing the properties of silicon carbide ceramics and alumina ceramics

Silicon carbide ceramics not only have excellent mechanical properties at room temperature, such as high flexural strength, excellent oxidation resistance, good corrosion resistance, high wear resistance and low friction coefficient, but also high temperature mechanical properties (strength, creep resistance) properties, etc.) is the best known ceramic materials. Hot pressing sintering, pressureless sintering, hot isostatic pressing sintering materials, the biggest feature of silicon carbide is high temperature strength, the strength of ordinary ceramic materials will be significantly reduced at 1200 ~ 1400 degrees Celsius, while the flexural strength of silicon carbide at 1400 degrees Celsius It is still maintained at a high level of 500 ~ 600MPa, so its working temperature can reach 1600 degrees Celsius; the silicon carbide plate is hard and brittle, with a small expansion coefficient, can withstand rapid cooling and heating, and is not easy to deform. Silicon carbide has the lowest density, so ceramic parts made of silicon carbide are the lightest.

 

Alumina ceramics is a ceramic material with alumina (Al2O3) as the main body, which is used in thick film integrated circuits. Alumina ceramics have good conductivity, mechanical strength and high temperature resistance. It should be noted that ultrasonic cleaning is required. Its wear resistance is equivalent to 266 times that of manganese steel and 171.5 times that of high-chromium cast iron. Alumina ceramics is a high-quality insulating material, which is often used to make ceramic insulating sheets, insulating rings and other components. The high temperature resistance of alumina ceramics can reach 1750 ° C (alumina content of more than 99%).

 

Alumina ceramics are white corundum wear-resistant ceramics fired in a 1700-degree high-temperature kiln. They have high hardness, light weight, no environmental pollution, and strong adhesion. They have excellent performance in equipment pipes, chutes and high temperature corrosion resistance. , and the price is low. Alumina ceramics have good electrical conductivity, mechanical strength and high temperature resistance. It should be noted that ultrasonic cleaning is required. Its wear resistance is 266 times that of manganese steel and 171.5 times that of high-chromium cast iron.

 

Alumina wear-resistant ceramic sheets can be directly processed into metal pipes lined with high wear-resistant alumina engineering ceramics. With its high cost performance, high hardness, good wear resistance, high temperature oxidation resistance, good corrosion resistance, powder resistance Known for aggressiveness, particle impact resistance and high temperature resistance.

 

Silicon carbide has the advantages of relatively low price, good corrosion resistance and high strength, but its biggest disadvantage is that it is easy to oxidize and difficult to sinter. Alumina ceramics are the cheapest, and the preparation process of powder raw materials is also very mature, and the latter two have obvious shortcomings in this regard, which is also one of the bottlenecks restricting the development of the latter two.